cool season annuals hort 308/609 assigned readings spring … · • limited range of soil moisture...
TRANSCRIPT
Cool Season AnnualsHORT 308/609
Plant List 6 Spring 2020
All Text And Images Are Copyrighted By:Dr. Michael A. Arnold, Texas A&M University,
Dept. Horticultural Sciences, College Station, TX 77843-2133
Assigned Readings for Plant List 6
Read the pages in your textbook associated with the
family descriptions and individual taxa covered on
Plant List 6 that was distributed in lab. These
plant lists are also available on the course website
A bit of landscaping helps most any structure!
Cool Season Annuals
• Tolerant of freezing to subfreezing temperatures– Suitable for use throughout winter
in southern half of our region– Suitable for late fall and very early
spring use in northern portions of the region
• Provides off-season color in winter
Cool season flowers
Cool season foliage
Cool (Season) Thoughts• Many species are derived from edible or
medicinal European species• Plants utilized solely for foliage are
more common than with other seasonal annuals
• Tall cool season annuals are infrequent, or become tall only late in the season
• Limited range of soil moisture is common• Most decline when day temperatures
consistently exceed 80°F or night temperatures exceed 70°F
• Mostly for detail designs, bedding, or seasonal containers
Alcea roseaHollyhocks
• Classic old-fashioned reseeding annual, biennial, or weak perennial
• Tolerates cold to USDA z. 5, but heat of z. 8 is tough• Bold coarse textured foliage; rounded mound the
first year or winter and then stiffly upright in spring
Alcea roseaHollyhocks
• Miniature hibiscus-like flowers– Singles quaint, doubles more formal
peony or carnation-like appearance– Flower stalks 3’ to 10’ depending on the
site conditions and cultivar selected– Colors vary from white, pink, red, to
purple, rarely pale yellow• Cotton root rot, spider mites, rust fungi, Japanese beetles
• Cottage gardens, strong vertical accent, spring borders
Rust fungi
Antirrhinum majusSnapdragon
• Cool season annual cut flower or bedding plant in southern parts of our region
• Fairly frost tolerant, transition annual in northern parts of our region
• 3” - 8” terminal racemes of pea-like flowers– White, pink, red, orange, yellow, purple,
2-tones; cyclic flushes on short types• 6” rounded mound to narrow upright & 5’ tall
• Sun to part shade, well drained moist soils; sun for bloom– Prone to rots and mildew in wet sites
• Summer heat and drought intolerant• Bedding, edging, containers, baskets, cut flowers
Antirrhinum majusSnapdragon
What is wrong with this
Antirrhinum majus?
Linaria spp.Toadflax
• Informal version of Snapdragon; 12”-18” tall; • Exotics add multiple colors; early spring bloom• Wildflower mixes, informal borders• Fall seed in south; late winter transplants north• Finer textured & even earlier bloom than
snapdragons; best as masses not individuals
Linaria spp.Toadflax
• Native species have pale blue to white flowers• Wildflower mixes, informal borders, early color
Color without flowers?Brassica oleracea
var. acephalaOrnamental CabbageOrnamental Kale
• Cool / cold season vegetable crop; variegated & dissected foliage types for landscape use– Green, white, red, purple combinations– Ruffled, dissected, 8” - 18” rosette of foliage
Cabbage looperdamage
Brassica oleracea var. acephalaOrnamental Cabbage or Kale
• Bolts (elongating flower spikes in spring)– Creamy white to pale yellow flowers, + or -– Bolting signals end of useful life– Fairly cold tolerant, remove immediately if
cold damaged, rotting foliage produces a foul odor; rotate beds to avoid diseases / pests
• Bedding, formal designs, accents, containers• Brassica oleracea var. capitata = head form
Brassica oleracea var. acephalaOrnamental Cabbage or Kale
This sometimes happens when you get a warm spell in late winter?
Brassica junceaGiant Mustard• Coarse textured bold rumpled
rugose foliage 1’ to 2’ tall• Dark purple-bronze leaves contrast
sharply with lighter veins• Vigorous and good cold tolerance
(ok in DFW); good in containers• Effective cool season massing plant
or in herb, cottage or kitchen garden
Beta vulgaris var. ciclaOrnamental Swiss Chard
• Ornamental Cabbage or Kale alternative• Handsome coarse bold colorful winter
foliage; edible, but not always palatable• Bronze, blue-green, to dark green
blades contrast with white, pink, purple, red, yellow or orange stalks and veins
• Use seed blends to retain color diversity
Not for flowers
Beta vulgaris var. ciclaOrnamental Swiss Chard
• Same species as edible beet; produces edible foliage, but does not form an edible root
• Full sun for best color; treat as an annual• Taller (18”) than many cool season color
plants; coarse bold texture
Lactuca sativaLettuce
• Classic edible green possessing a variety of foliage forms, textures, and colors with ornamental potential
• Can be effective in cold of USDA z. 6 to 8, but is not heat tolerant
• Lots of foliage pests, but a very rapid grower; lush temporary filler plant
• Cottage garden; educational gardens; accent plantings; container gardens
Lactuca sativaLettuce
• Excellent example of a dual purpose plant which could be incorporated in sustainable landscapes
• Conventional production, hydroponics of many forms, containers or even living wall culture can all be significant
• Also effective for attracting wildlife
Cynara cardunculusCardoon
• 1’-2’ (3’) tall coarse textured blue-green to silver-green mound of foliage in winter
• Bolting to 5’ to 6’ in spring• Strong accent / background plant
Cynara cardunculusCardoon
• Iridescent blue thistle-like flowers • Herb, cottage, heritage gardens• Close relative of Globe Artichoke,
Cynara scolymus; z. 8 (7)-10 (11)
Calendula officinalisPot Marigold
• A classic cottage garden plant grown for medicinal purposes, later converted for ornamental use; dual purpose plant
• Daisy to Zinnia-like, yellow to orange flowers
• Intensely bright to more pastel cultivars
Calendula officinalisPot Marigold
• Cool to transition season annual• Powdery mildew, slugs, and spider
mites are periodic problems• Sunny site in well drained moist soil• Bedding (variable sizes available),
massing, or cut flower gardens; cottage and children’s gardens; medicinal gardens; patio containers
Cyclamen persicumFlorist’s Cyclamen
• Red, pink, white, to purple flowers atop a dense mound of violet-like foliage
• Unique inverted flowers held above foliage
• Long season of effectiveness• Effective for bedding, containers, detail
work, cool high light interiorscapes
Cyclamen persicumFlorist’s Cyclamen
• Shade to morning sun; needs moist rich soils; not heat or drought tolerant
• Tubers can be lifted & stored in cool & dry location in summer
• Summer dormancy• Cool season annual
USDA z. 9 & warmer
Cyclamen persicumFlorist’s Cyclamen
What caused this problem?
Dianthus chinensisChina Pinks
• Short-lived perennials used as cool season annuals– Effective fall - early summer in TX– Popular summer annual in central
and northern regions of USA• Short, 6” - 12” tall, compact
mound, medium / fine texture• Profusion of white, pink, red
or two-tone flowers– Color range & size are expanding– Peak spring bloom, some flowers
fall and winter
Dianthus chinensisChina Pinks
• Best in rich organic soils, but tolerates less fertile sites
• Crown rot in wet soils, melts in Texas’ summer heat
• One of best cool season color plants for Texas
Eschscholzia californica California Poppy
• Outstanding as a cool season annual • Sprawling mound 1’ to 2’ tall• Rich green / blue-green finely
divided foliage contrasts with bright orange flowers
Eschscholzia californicaCalifornia Poppy
• Use in sunny site with well drained soils, dependable if winters are not too cold
• Excellent accent, massing, informal beds, naturalizing
• Expanding range of flower colors
• Rotate plantings due to Sclerotinia root & crown rots
Eschscholzia californica subsp. mexicana is native to El Paso area
Vistas in foothills of Franklin Mountains near El Paso, Texas courtesy of Dr. Geoff Denny
Papaver spp.Poppies
• Group of species used in warm climates as cool or transition season annuals or as herbaceous perennials in cooler climates
• Most with a rosette-like growth form until flowering commences when stalks elongate
• Most species are planted for the large 3” to 6” diameter cup-shaped or peony-like flowers
Papaver spp.Poppies
• Flowers come in a variety of iridescent colors and petals have a tissue-paper like texture
• Place in sun, well drained soils, foliage dies down in summer
• Source of pharmaceuticals and illegal drugs; also culinary uses
Lathyrus odoratusAnnual Sweet Pea
• Short, 6’ to 8’ tall, weakly climbing to sprawling blue-green vine with tendrils
• Pea-shaped blue, pink, red to white fragrant spring flowers; fruit inedible
• Rare cool season trellis / fence cover, fragrant cut flowers; naturalizing
• Tolerate frost, but not hard freezes
Limonium sinuatumAnnual Statice
• Cool to transition annual; low flat rosettes of foliage with 1’ to 2’ stalks topped by wind-sweep 4”- 8” long x 1”- 2” wide inflorescences
• Showy white, pink, pink-orange, lavender, yellow, or blue calyx
• Tall bedding, accent, cut or dried arrangements
Lobularia maritimaSweet Alyssum
• Low growing 4” to 6” tall spreading cool to transition season annuals; summers in north
• Long bloom season of white, pink, purple, to maroon fragrant flowers
• Root rots in poor soils & takes limited heat, otherwise trouble-free
• General bedding, rock gardens, living walls, containers, edging, detail work, fragrance gardens
‘Snow Princess’
Matthiola incanaStock
• Upright oval to erect 8” to 36” tall cool or transition season annuals; blue-green foliage; recurring bloom
• Single or double, white, pink, red, purple, mauve highly fragrant flowers
Matthiola incanaStock
• Neither heat nor drought tolerant• Massing, bedding, or perhaps
edging with shorter cultivars• Cut flowers, background of
beds, borders, heritage gardens
Primula × polyanthaPolyanthusPrimrose
• Mild climate [z. 7b-9a(9b)] herbaceous perennial grown here as winter annual
• Dark rugose (quilted) coarse green leaves in rosettes
• Clusters of 1”+ flowers above foliage
Primula × polyanthaPolyanthus Primrose
• Bright white, yellow, gold, bronze, brown, pink, red, purple, blue or two-tone flowers
• Root / crown rots, spider mites, slugs
• Bedding, accents, containers; large taproot
Viola × wittrockianaPansy
• Premier cool season annual for Texas and SE USA– Heat intolerant– Widely used as transition
annuals in cooler regions
• Compact rounded to sprawling mound, 4” -10” tall, heat intolerant– Attractive dark glossy green
leaves contrast with flowers– High N requirements– Avoid excess PGR use
Viola × wittrockiana Pansy
• Flat, circular flower held vertically, huge color range– Old-fashion flowers with “face”
in flower, two-tone or tricolor +– Solids, marbles, bright to pastel– Nearly every color of
rainbow except maybe green• Rotate beds to avoid disease
problems, needs drainage
Viola × wittrockiana Pansy• Carry-over problems with excess growth regulators
With growth regulator
No growth regulator
Viola × wittrockiana PansyOft used as cool season filler or as layered bloom
Beware of color contrast as Pansies
overlap bloom of other cool season color
Viola tricolorJohnny-Jump-Up• Wild European Pansy, naturalized in
several portions of USA• Smaller 3-color, purple, blue, & yellow
flowers than V. × wittrockiana• Flowers in profusion, readily reseeds• Initially upright then sprawling growth
form and finer textured than V. ×wittrockiana, use in dense masses
• Under-utilized for durable spring color• Older cultivars replaced in commercial
trade by Viola cornuta (Horned Violet) cultivars and hybrids with V. cornuta
Species type
Lupinustexensis
Texas Bluebonnet• Regionally most common Lupinus spp.
• Rosette or clump-like winter annual– Seven Lupinus spp. native to Texas, all designated Texas’ state flower– Effective as short duration spring bedding plants or for naturalizing
Lupinustexensis
TexasBluebonnet
• Spike or racemes of pea-like flowers– Classic blue with white or pink spots, also available in white, pink,
lavender, red and maroon; fragrant waves of blue in spring• Best if direct seeded in fall, spring transplants not as effective
Genisa broom moth(Uresiphita reversalis)
Castilleja indivisaIndian Paintbrush
• Natural companion plant to Lupinus spp.– Facultative parasitic on several
genera including Lupinus• Cool season annual wildflower• Famous for spikes of red to
orange bracts at same time as bluebonnets
• Difficult to transplant, poor garden plant, best used for naturalizing
• Of cultural significance to native Americans
Additional images may be viewed on Plant Picture Pages on
http://landscapeplants.tamu.edu
Materials presented herein are copyrighted as indicated or by Michael A. Arnold; for permission to use or reproduce these
images, please write:Dr. Michael A. Arnold
Dept. of Horticultural SciencesTexas A&M University
College Station, TX 77843-2133email [email protected]